[Impact of tobacco use on the periodontium--an update. Part 2: Clinical and radiographic changes in the periodontium and effects on periodontal and implant therapy]

This third part of a series of publications from the Swiss task force "Smoking--Intervention in the private dental office" on the topic "tobacco use and dental medicine" describes the clinical and radiographic changes of the periodontium within smokers as well as the consequences of tobacco use on periodontal and implant therapy. With increased use of tobacco, patients show higher periodontal probing depths, increased clinical attachment loss, more alveolar bone resorption, a higher prevalence of gingival recessions, and a higher risk for tooth loss. In contrast to this, with smokers, the clinical characteristics of gingival inflammation or bleeding on periodontal probing are less established. Smokers show less positive results after conventional, surgical and regenerative periodontal therapy. The benefits of mucogingval surgery are reduced and less successful in smokers. Moreover, smoking impairs the osseointegration of oral implants and is at least partly responsible for a majority of biological complications in implant dentistry, such as periimplantitis. Based on the present understanding of periodontal diseases, the clinical findings, and the specific therapeutic outcomes with smokers, it appears to be reasonable, next to the current classification of periodontal diseases, to use the term "smokers periodontitis".

An investigation of computer literacy and attitudes amongst Greek post-graduate dental students

An accurate assessment of the computer skills of students is a pre-requisite for the success of any e-learning interventions. The aim of the present study was to assess objectively the computer literacy and attitudes in a group of Greek post-graduate students, using a task-oriented questionnaire developed and validated in the University of Malmö, Sweden. 50 post-graduate students in the Athens University School of Dentistry in April 2005 took part in the study. A total competence score of 0-49 was calculated. Socio-demographic characteristics were recorded. Attitudes towards computer use were assessed. Descriptive statistics and linear regression modeling were employed for data analysis. Total competence score was normally distributed (Shapiro-Wilk test: W = 0.99, V = 0.40, P = 0.97) and ranged from 5 to 42.5, with a mean of 22.6 (+/-8.4). Multivariate analysis revealed 'gender', 'e-mail ownership' and 'enrollment in non-clinical programs' as significant predictors of computer literacy. Conclusively, computer literacy of Greek post-graduate dental students was increased amongst males, students in non-clinical programs and those with more positive attitudes towards the implementation of computer assisted learning.

Patient satisfaction and side effects in primary care: An observational study comparing homeopathy and conventional medicine

Background This study is part of a nationwide evaluation of complementary medicine in Switzerland (Programme Evaluation of Complementary Medicine PEK) and was funded by the Swiss Federal Office of Public Health. The main objective of this study is to investigate patient satisfaction and perception of side effects in homeopathy compared with conventional care in a primary care setting. Methods We examined data from two cross-sectional studies conducted in 2002–2003. The first study was a physician questionnaire assessing structural characteristics of practices. The second study was conducted on four given days during a 12-month period in 2002/2003 using a physician and patient questionnaire at consultation and a patient questionnaire mailed to the patient one month later (including Europep questionnaire). The participating physicians were all trained and licensed in conventional medicine. An additional qualification was required for medical doctors providing homeopathy (membership in the Swiss association of homeopathic physicians SVHA). Results A total of 6778 adult patients received the questionnaire and 3126 responded (46.1%). Statistically significant differences were found with respect to health status (higher percentage of chronic and severe conditions in the homeopathic group), perception of side effects (higher percentage of reported side effects in the conventional group) and patient satisfaction (higher percentage of satisfied patients in the homeopathic group). Conclusion Overall patient satisfaction was significantly higher in homeopathic than in conventional care. Homeopathic treatments were perceived as a low-risk therapy with two to three times fewer side effects than conventional care

High-resolution computer simulation of electrophoretic mobilization in isoelectric focusing

Cationic and anionic electrophoretic mobilization for focusing of hemoglobins (Hb's) in the presence of 100 carrier ampholytes covering a pI range of 6.00-7.98 was studied by computer simulation at a constant current density of 300 A/m(2). Electropherograms that would be produced by whole column imaging and by single detectors placed at different locations along the focusing column are presented. Upon mobilization, peak heights of the Hb zones decrease, but the zones retain a relatively sharp constant profile and are migrating at a constant velocity. A further peak decrease occurs during readjustment at the locations of the original buffer/column interfaces, indicating that detection sensitivity is the lowest at these locations. An anionic carrier ampholyte mobility smaller than that of its cationic species produces a cathodic drift which is smaller than the transport rate used for electrophoretic mobilization. Compared to the case with equal mobilities of carrier ampholyte species, a small increase (decrease) is predicted for the cationic (anionic) mobilization rate within the focusing column. Simulation data suggest that electrophoretic mobilization after focusing and focusing with concurrent electrophoretic mobilization are comparable isotachophoretic processes that occur when there is an uninterrupted flux of an ion through the focusing column. Cathodic drift caused by unequal mobilities of the species of carrier ampholytes, electrophoretic mobilization, and decomposition occurring at the pH gradient edges are related electrophoretic processes.

Effects of troglitazone on cellular differentiation, insulin signaling, and glucose metabolism in cultured human skeletal muscle cells

To determine the immediate effect of thiazolidinediones on human skeletal muscle, differentiated human myotubes were acutely (1 day) and myoblasts chronically (during the differentiation process) treated with troglitazone (TGZ). Chronic TGZ treatment resulted in loss of the typical multinucleated phenotype. The increase of muscle markers typically observed during differentiation was suppressed, while adipocyte markers increased markedly. Chronic TGZ treatment increased insulin-stimulated phosphatidylinositol (PI) 3-kinase activity and membranous protein kinase B/Akt (PKB/Akt) Ser-473 phosphorylation more than 4-fold. Phosphorylation of p42/44 mitogen-activated protein kinase (42/44 MAPK/ERK) was unaltered. Basal glucose uptake as well as both basal and insulin-stimulated glycogen synthesis increased approximately 1.6- and approximately 2.5-fold after chronic TGZ treatment, respectively. A 2-fold stimulation of PI 3-kinase but no other significant TGZ effect was found after acute TGZ treatment. In conclusion, chronic TGZ treatment inhibited myogenic differentiation of that human muscle while inducing adipocyte-specific gene expression. The effects of chronic TGZ treatment on basal glucose transport may in part be secondary to this transdifferentiation. The enhancing effect on PI 3-kinase and PKB/Akt involved in both differentiation and glycogen synthesis appears to be pivotal in the cellular action of TGZ.

Gastroesophageal reflux and pulmonary fibrosis in scleroderma: a study using pH-impedance monitoring

RATIONALE: Interstitial lung disease (ILD) in patients with systemic sclerosis (SSc) is associated with increased morbidity and mortality. Gastroesophageal reflux (GER) is considered a contributing factor in the pathogenesis of ILD. OBJECTIVES: To characterize GER (acid and nonacid) in patients with SSc with and without ILD. METHODS: Patients with SSc underwent pulmonary high-resolution computer tomography (HRCT) scan and 24-hour impedance-pH monitoring off-proton pump inhibitor therapy. The presence of pulmonary fibrosis was assessed using validated HRCT-scores. Reflux monitoring parameters included number of acid and nonacid reflux episodes, proximal migration of the refluxate, and distal esophageal acid exposure. Unless otherwise specified, data are presented as median (25th-75th percentile). MEASUREMENTS AND MAIN RESULTS: Forty consecutive patients with SSc (35 female; mean age, 53 yr; range, 24-71; 15 patients with diffuse and 25 with limited SSc) were investigated; 18 (45%) patients with SSc had pulmonary fibrosis (HRCT score >or= 7). Patients with SSc with ILD had higher (P < 0.01) esophageal acid exposure (10.3 [7.5-15] vs. 5.2 [1.5-11]), higher (P < 0.01) number of acid (41 [31-58] vs. 19 [10-23]) and nonacid (25 [20-35] vs. 17 [11-19]) reflux episodes, and higher (P < 0.01) number of reflux episodes reaching the proximal esophagus (42.5 [31-54] vs. 15 [8-22]) compared with patients with SSc with normal HRCT scores. Pulmonary fibrosis scores (HRCT score) correlated well with the number of reflux episodes in the distal (r(2) = 0.637) and proximal (r(2) = 0.644) esophagus. CONCLUSIONS: Patients with SSc with ILD have more severe reflux (i.e., more reflux episodes and more reflux reaching the proximal esophagus). Whether or not the development of ILD in patients with SSc can be prevented by reflux-reducing treatments needs to be investigated.

Intra- and inter-individual variation of BIS-index and Entropy during controlled sedation with midazolam/remifentanil and dexmedetomidine/remifentanil in healthy volunteers: an interventional study

INTRODUCTION: We studied intra-individual and inter-individual variability of two online sedation monitors, BIS and Entropy, in volunteers under sedation. METHODS: Ten healthy volunteers were sedated in a stepwise manner with doses of either midazolam and remifentanil or dexmedetomidine and remifentanil. One week later the procedure was repeated with the remaining drug combination. The doses were adjusted to achieve three different sedation levels (Ramsay Scores 2, 3 and 4) and controlled by a computer-driven drug-delivery system to maintain stable plasma concentrations of the drugs. At each level of sedation, BIS and Entropy (response entropy and state entropy) values were recorded for 20 minutes. Baseline recordings were obtained before the sedative medications were administered. RESULTS: Both inter-individual and intra-individual variability increased as the sedation level deepened. Entropy values showed greater variability than BIS(R) values, and the variability was greater during dexmedetomidine/remifentanil sedation than during midazolam/remifentanil sedation. CONCLUSIONS: The large intra-individual and inter-individual variability of BIS and Entropy values in sedated volunteers makes the determination of sedation levels by processed electroencephalogram (EEG) variables impossible. Reports in the literature which draw conclusions based on processed EEG variables obtained from sedated intensive care unit (ICU) patients may be inaccurate due to this variability. TRIAL REGISTRATION: clinicaltrials.gov Nr. NCT00641563.

Sprouting and intussusceptive angiogenesis in postpneumonectomy lung growth: mechanisms of alveolar neovascularization

In most rodents and some other mammals, the removal of one lung results in compensatory growth associated with dramatic angiogenesis and complete restoration of lung capacity. One pivotal mechanism in neoalveolarization is neovascularization, because without angiogenesis new alveoli can not be formed. The aim of this study is to image and analyze three-dimensionally the different patterns of neovascularization seen following pneumonectomy in mice on a sub-micron-scale. C57/BL6 mice underwent a left-sided pneumonectomy. Lungs were harvested at various timepoints after pneumonectomy. Volume analysis by microCT revealed a striking increase of 143 percent in the cardiac lobe 14 days after pneumonectomy. Analysis of microvascular corrosion casting demonstrated spatially heterogenous vascular densitities which were in line with the perivascular and subpleural compensatory growth pattern observed in anti-PCNA-stained lung sections. Within these regions an expansion of the vascular plexus with increased pillar formations and sprouting angiogenesis, originating both from pre-existing bronchial and pulmonary vessels was observed. Also, type II pneumocytes and alveolar macrophages were seen to participate actively in alveolar neo-angiogenesis after pneumonectomy. 3D-visualizations obtained by high-resolution synchrotron radiation X-ray tomographic microscopy showed the appearance of double-layered vessels and bud-like alveolar baskets as have already been described in normal lung development. Scanning electron microscopy data of microvascular architecture also revealed a replication of perialveolar vessel networks through septum formation as already seen in developmental alveolarization. In addition, the appearance of pillar formations and duplications on alveolar entrance ring vessels in mature alveoli are indicative of vascular remodeling. These findings indicate that sprouting and intussusceptive angiogenesis are pivotal mechanisms in adult lung alveolarization after pneumonectomy. Various forms of developmental neoalveolarization may also be considered to contribute in compensatory lung regeneration.

QoE-aware Multiple Path Video Transmission for Wireless Multimedia Sensor Networks

Wireless Multimedia Sensor Networks (WMSNs) promise a wide scope of emerging potential applications in both civilian and military areas, which require visual and audio information to enhance the level of collected information. The transmission of multimedia content requires a minimal video quality level from the user’s perspective. However, links in WMSN communi- cations are typically unreliable, as they often experience fluctuations in quality and weak connectivity, and thus, the routing protocol must evaluate the routes by using end-to-end link quality information to increase the packet delivery ratio. Moreover, the use multiple paths together with key video metrics can enhance the video quality level. In this paper, we propose a video-aware multiple path hierarchical routing protocol for efficient multimedia transmission over WMSN, called video-aware MMtransmission. This protocol finds node-disjoint multiple paths, and implements an end-to-end link quality estimation with minimal over- head to score the paths. Thus, our protocol assures multimedia transmission with Quality of Experience (QoE) and energy-efficiency support. The simula- tion results show the benefits of video-aware MMtransmission for disseminating video content by means of energy-efficiency and QoE analysis.

A Process Model of Complementarity and Substitution of Contractual and Relational Governance in IS Outsourcing

This paper develops a process model of how and why complementarity and substitution form over time between contractual and relational governance in the context of information systems outsourcing. Our analysis identifies four distinct process patterns that explain this formation as the outcome of interaction processes between key elements of both contractual and relational governance. These patterns unveil the dynamic nature of complementarity and substitution. In particular, we show that the relationship between contractual and relational governance oscillates between complementarity and substitution. Those oscillations are triggered mainly by three types of contextual events (goal fuzziness, goal conflict, and goal misalignment). Surprisingly, substitution of informal control did not occur as an immediate reaction to external events but emerged as a consequence of preceding complementarity. Thus, our study challenges the prevailing view of an either/or dichotomy of complementarity and substitution by showing that they are causally connected over time.

Ecosystem services, biodiversity and environmental change in a tropical mountain ecosystem of south Ecuador

An interdisciplinary research unit consisting of 30 teams in the natural, economic and social sciences analyzed biodiversity and ecosystem services of a mountain rainforest ecosystem in the hotspot of the tropical Andes, with special reference to past, current and future environmental changes. The group assessed ecosystem services using data from ecological field and scenario-driven model experiments, and with the help of comparative field surveys of the natural forest and its anthropogenic replacement system for agriculture. The book offers insights into the impacts of environmental change on various service categories mentioned in the Millennium Ecosystem Assessment (2005): cultural, regulating, supporting and provisioning ecosystem services. Examples focus on biodiversity of plants and animals including trophic networks, and abiotic/biotic parameters such as soils, regional climate, water, nutrient and sediment cycles. The types of threats considered include land use and climate changes, as well as atmospheric fertilization. In terms of regulating and provisioning services, the emphasis is primarily on water regulation and supply as well as climate regulation and carbon sequestration. With regard to provisioning services, the synthesis of the book provides science-based recommendations for a sustainable land use portfolio including several options such as forestry, pasture management and the practices of indigenous peoples. In closing, the authors show how they integrated the local society by pursuing capacity building in compliance with the CBD-ABS (Convention on Biological Diversity - Access and Benefit Sharing), in the form of education and knowledge transfer for application.